Resilient retainer



March 28, 1967 w.J.l.l-:1TMANN 3,311,393

RES ILIENT RETAINER Filed April 1,5, 1965 INVENTOR. WILLIAM J, LEITMANN United States Patent O 3,311,393 RESILIENT RETAINER William J. Leitmann, Chicago, Ill., assignor to Rohden Manufacturing Company, Inc., Chicago, Ill., a corporation of Illinois Filed Apr. 13, 1965, Ser. No. 447,797 4 Claims. (Cl. 287-53) This invention is directed to a new and improved resilient retainer for use in releasably securing members such as, for example, mounting a control knob on a shaft.

In its broadest sense, the resilient retainer of the present invention includes a generally flat plate-like mounting portion of generally rectangular outline having an undulated flap portion disposed centrally of the rectangle and integral with the at plate-like portion along one marginal edge.

When the plate-like mounting portion is disposed within a bore formed in a knob and having a at side, and a co-operating dat sided shaft is inserted, the undulated portion is exed along the intersection of the plate-like portion and the flap to urge a portion of the flat platelike mounting portion into engagement with the shaft while opposite sides -of the undulations are positioned along the the outer edges of the flat portion of the shaft to reduce backlash or expressed another way, to prevent relative rotation between the shaft and knob.

Resilient retainers or knob springs as they are sometimes called are not in and of themselves new to the trade. In fact, resilient retainers which act against the flat sided shaft and flat sided bore of the knob are well known and have received notable acceptance in the industry because they afford several rather remarkable advantages, notable among which is the ability to permit repeated removal and reassembly of the knob to the shaft by application of force generally parallel to or along the axis of the shaft. The retainer of the present invention adds to these advantages being conveniently and easily installed within a bore in a knob and as mentioned above, serves to exert pressure along unique points to minimize backlash and guard against inadvertent displacement of the knob. Notwithstanding the numerous favorable advantages obtained by the resilient retainer of the present invention, it is capable of l-ow cost manufacture and installation. Retainers of the .present type are manufactured and sold in large quantities, being stamped from untempered metal plate and thereafter heat treated to insure good resilience.

A better understanding of the present invention and the vbenefits and advantages obtained by its implementation may be had by considering the more prominent objects to be achieved and a detailed description of a preferred embodiment which follows.

It is an object of the invention to provide a new and improved spring for mounting in a bore in a knob or other suitable member for resilient engagement with a shaft-like means adapted to be received in the knob bore.

It is a further object of this invention to provide a resilient retainer of simplified form which minimizes the raw material used thereby contributing to ec-onomical manufacture and assembly.

A further object of this invention is to provide a new and improved resilient retainer in which the rotational pressure points are disposed outwardly of the central rotational axis thereby to maximize the grip between the knob and shaft which in turn minimizes backlash.

Still a further object of the invention is to provide a new and improved resilient retainer having a uniquely shaped spring leaf portion integrally formed with a platelike mountin portion which is capable of frictionally and releasably interconnecting a knob with a shaft-like means.

Further and fuller objects will become readily apparent when reference is made to the accompanying drawings wherein:

FIG. l is a free body perspective view of the resilient retainer of the present invention;

FIG. 2 is a rear elevational view of a knob having a flat sided bore in which the resilient retainer of FIG. 1 is positioned;

FIG. 3 is a cross sectional view through the knob of FIG. 2 with the retainer being shown in full side elevation; and

FIG. 4 is a view similar to FIG. 3 illustrating the condition assumed by the resilient retainer after insertion of a flat sided shaft-like means which is shown fragmentarily.

In FIG. 1 reference numeral 10 indicates the resilient retainer of the present invention including a generally flat plate-like mounting portion 11 having a central undulated flap portion 12 severed from the plate 11 on three sides to form a free end portion while the opposite end is integral with the plate-like portion along the remaining side. The plate-like mounting portion 11 is of generally rectangular outline when viewed in plan, having enlarged or bowed side marginal edges 13 and 14 which imparta wedge shape to the spring for purposes to become apparent.

The integral flap portion 12 is formed by severing the plate 11 along the edges 15 and 16 and across the free end 17. During or after the severing operation a single undulation 18 is formed centrally 'of the ap merging smoothly into spaced shaft engaging portions 19 and 2) which as seen in FIG. 2 are disposed above a plane lying in the plate-like mounting portion.

On inspection of FIGS. l and 2, it is readily apparent that the shaft engaging portions 19 and 20 of the flap 12 are disposed outwardly of the central axis of the knob for resilient engagement with a at sided shaft outwardly of the axis of rotation. The undulation 18 projects below the plate-like portion 11 and is received in a spring groove 21 formed in the knob 22 permitting exing and enhancing the ease of assembly. The wedge-shaped marginal edges 13 and 14 engage side portions 23 and -24 of the bore 25 in the knob 22 with a tight fit to hold the retainer 10 within the knob.

The bore 25 in the knob 22 may be of any shape or size such as arcuate or triangular as shown so long as it is provided with a at bottom portion 26 and a relieved portion 21 to receive the undulation 18. Obviously, if clearances permit, the relieved portion 21 may be omitted.

In the cross sectional view of FIGS. 3 and 4, it can be observed that the retainer spring lil in the unflexed state is assembled in the knob 22 with the plate-like mounting portion 11 lying against the flat side 26 of the bore 25. The resilient ap 12 has the single undulation 18 disposed in the relieved portion 21 while the shaft engaging portions 19 and 20 (only 20 shown in FIG. 3) extend above the plate-like mounting portion into the central region ofthe bore 25.

As shaft-like means such as the one indicated fragmentarily at 27 is provided with a flat portion as at 28 which is adapted for insertion into the bore 25 formed in the knob 22. As best seen in FIG. 4, when the shaftlike means 27 is inserted, the shaft engaging portions 19 and 20 force the undulation 18 downwardly in the groove 21. This causes the transverse or rear edge 31 of the plate-like mounting portion 11 to flex along a hinge axis generally passing transversely through the junctions formed by flap 12 and the edges 15 and 16. Such hinge axis is identified by reference numeral 30 in FIG. 4. This flexing in turn causes the rear edge portion 31 to be biased upwardly into engagement with the flat side 28 of the shaft 27 across an area of the flat 28 which is axially spaced from the shaft engaging portions 19 and 20 to releasably join the knob 22 to the shaft 27.

Referring once again to FIG. 2, it can be appreciated that rotational motion transmitted through the knob to the shaft passes through the fiat plate 11 and the shaft engaging portions 19 and 20 to the fiat side of the shaft. Relative rotation between the shaft 27 and knob 22 is resisted at these three points (areas) thus substantially eliminating backlash.

From the foregoing description it is obvious that the retainer spring of the present invention is adapted for other uses such as connecting the lead terminal cap to a vacuum tube, joining two flat sided shafts in axial relationship through a connecting collar or the like. Obviously, other uses are suggested by inspection lof the present design. It is equally obvious that the retainer spring of the present invention may be inserted in the knob opposite the direction shown precluding assembly errors,

Upon a consideration of the foregoing, it will become obvious to those skilled in the art that various modications may be made without departing from the invention embodied herein. Therefore, any limitations imposed are intended to be within the spirit and scope of the appended claims.

I claim:

1. In an arrangement wherein a shaft-like means is joined to a knob, said shaft-like means having at least one hat side, and said knob having a bore to receive said shaft including a longitudinally extending tiat side portion for cooperation with the flat side of said shaft-like means, a relief groove formed in said flat side portion and extending longitudinally of said bore, the improvement comprising a resilient retainer for releasably joining said shaft-like means to said knob to transmit rotational forces in a backlash-free manner, said resilient retainer including a plate-like mounting portion adapted for interposition between the at side on said shaft-like means and flat side portion of said bore, a flap portion formed centrally of said plate-like mounting portion and having a free end portion disposed above a plane passing through said plate-like mounting portion, said ap portion having an undulation formed at the free end thereof and extending transversely of the longitudinal axis of said plate-like mounting portion, said undulation being adapted to be received in said relief groove, a pair of shaft engaging portions formed on opposite sides of said undulation, said shaft engaging portions being disposed above said plate-like mounting portion and adapted for engagement with the fiat side of said shaft-like means, said undulation in said iiap portion extending below said platelike portion and the end portion of said flap opposite the free end portion being formed integral with a transverse end portion on said plate-like mounting portion, said end portion being adapted to be flexed upwardly into engagement with said shaft-like means as said shaft engaging portions are engaged by said shaft-like means.

2. A resilient retainer for releasably joining a shaftlike means to a knob for backlash free rotations comprising, a plate-like mounting portion having a longitudinal axis and wedge-shaped side edge portions adapted for engagement with a bore formed in said knob, a flap portion formed between said side edge portions being struck from said plate-like mounting portion and having a free end portion, the end opposite said free end portion being integral with said side edge portions through a transversely extending rear edge portion, said ap portion having an undulation formed transversely of said longitudinal axis at the free end portion and a pair of shaft engaging portions formed on opposite sides of said undulation for resilient engagement with said shaft-like means, said undulation being disposed on one side of said plate-like mounting portion and said shaft engaging portions disposed on the other side of said plate-like mounting portion thereby to move said transversely extending rear edge portion into engagement with said shaft-like means when intertted between said knob and said shaft-like means.

3. A resilient retainer adapted for use in joining a shaft-like means to a knob, said resilient retainer including a plate-like mounting portion having side edge portions adapted for engagement with a bore in said knob, a transverse end portion extending between said side edge portions and having a flap portion struck from said platelike mounting portion, said ap portion having an undulation formed at a free end portion and extending transversely of the longitudinal axis of said plate-like mounting portion, a pair of spaced shaft engaging portions formed on opposite sides of said undulation for engagement with said shaft-like means outwardly of the rotational axis thereof, said undulation being disposed on one side of said plate-like mounting portion and said shaft engaging portion being disposed on an opposite side of said plate-like mounting portion, said flap portion being adapted to be flexed relative to said plate-like mounting portion thereby to move said transverse end portion upwardly into engagement with said shaft-like means.

4. A resilient retainer for use in releasably joining a shaft-like means to a knob for transmitting rotational forces therebetween, said shaft-like means having at least one at side, said knob having a bore of conforming shape including a longitudinally extending at side portion adapted for cooperation with said shaft-like means, a relief groove formed in said bore in said hat side portion and extending longitudinally of said bore, said spring retainer including a plate-like mounting portion interposed between said shaft and the hat side portion of said bore, a iiap portion formed centrally of said plate-like mounting portion, said flap portion being struck from said plate-like mounting portion and having a free end portion, an undulation formed transversely of the longitudinal axis of said plate-like mounting portion on the free end portion of said ap portion, said undulation extending into said relief groove, a pair of shaft engaging portions on opposite sides of said undulation, said shaft engaging portions being disposed above said plate-like mounting portions on the side opposite of said undulation, and an end portion formed transversely of said flap portion, said end portions being exed into engagement with said shaftlike means of said shaft engaging portions are engaged by said shaft.

References Cited by the Examiner UNITED STATES PATENTS 1,918,115 7/1933 Luft 267-1 3,130,990 4/1964 Leitmann 287-53 FOREIGN PATENTS 652,978 5/1951 Great Britain.

CARL W` TOMLIN, Primary Examiner.

A. V. KUNDRAT, Assistant Examiner. Y 

1. IN AN ARRANGEMENT WHEREIN A SHAFT-LIKE MEANS IS JOINED TO A KNOB, SAID SHAFT-LIKE MEANS HAVING AT LEAST ONE FLAT SIDE, AND SAID KNOB HAVING A BORE TO RECEIVE SAID SHAFT INCLUDING A LONGITUDINALLY EXTENDING FLAT SIDE PORTION FOR COOPERATION WITH THE FLAT SIDE OF SAID SHAFT-LIKE MEANS, A RELIEF GROOVE FORMED IN SAID FLAT SIDE PORTION AND EXTENDING LONGITUDINALLY OF SAID BORE, THE IMPROVEMENT COMPRISING A RESILIENT RETAINER FOR RELEASABLY JOINING SAID SHAFT-LIKE MEANS TO SAID KNOB TO TRANSMIT ROTATIONAL FORCES IN A BACKLASH-FREE MANNER, SAID RESILIENT RETAINER INCLUDING A PLATE-LIKE MOUNTING PORTION ADAPTED FOR INTERPOSITION BETWEEN THE FLAT SIDE ON SAID SHAFT-LIKE MEANS AND FLAT SIDE PORTION OF SAID BORE, A FLAP PORTION FORMED CENTRALLY OF SAID PLATE-LIKE MOUNTING PORTION AND HAVING A FREE END PORTION DISPOSED ABOVE A PLANE PASSING THROUGH SAID PLATE-LIKE MOUNTING PORTION, SAID FLAP PORTION HAVING AN UNDULATION FORMED AT THE FREE END THEREOF AND EXTENDING TRANSVERSELY OF THE LONGITUDINAL AXIS OF SAID PLATE-LIKE MOUNTING PORTION, SAID UNDULATION BEING ADAPTED TO BE RECEIVED IN SAID RELIEF GROOVE, A PAIR OF SHAFT ENGAGING PORTIONS FORMED ON OPPOSITE SIDES OF SAID UNDULATION, SAID SHAFT ENGAGING PORTIONS BEING DISPOSED ABOVE SAID PLATE-LIKE MOUNTING PORTION AND ADAPTED FOR ENGAGEMENT WITH THE FLAT SIDE OF SAID SHAFT-LIKE MEANS, SAID UNDULATION IN SAID FLAP PORTION EXTENDING BELOW SAID PLATELIKE PORTION AND THE END PORTION OF SAID FLAP OPPOSITE THE FREE END PORTION BEING FORMED INTEGRAL WITH A TRANSVERSE END PORTION ON SAID PLATE-LIKE MOUNTING PORTION, SAID END PORTION BEING ADAPTED TO BE FLEXED UPWARDLY INTO ENGAGEMENT WITH SAID SHAFT-LIKE MEANS AS SAID SHAFT ENGAGING PORTIONS ARE ENGAGED BY SAID SHAFT-LIKE MEANS. 